Will contingent maternal responding to nondistress infant crying lead to a subsequent decrease in that crying (as the 1972 Bell and Ainsworth conclusion has led many to expect) or will it lead to a crying-rate increase (as would be expected under instrumental learning theory)? Subjects were 12- to 14-week old normal infants. Infant lay on floor, alone in room with door ajar. The cry response was defined as a 5-sec. shrill or whiney vocalization, accompanied by a facial grimace. Under noncontingent responding, mother entered routinely at 1-min. intervals to visit her infant, provided s/he was not crying. Under contingent responding, mother's visits were contingent on infant's 5-sec. cries. Number of maternal 10-sec. visits (i.e., stimulus density) was comparable under both treatments. Mother acted naturally, but did not pick up infant. Compared to mothers' noncontingent responding, their contingent responding systematically increased their infants' mean crying rates (p less than .012). Therefore, maternal responding contingent on infant nondistress cries increased the cry rate as expected under instrumental-learning theory. This result has implications for the caregiver management of infant crying.